The comparison was to Model X third-row (the two rear seats), which has no shoulder room. I am expecting I-Pace to do better on its second row.
Well, he's talking about the middle seat of the 2nd row of the I-Pace compared to the 3rd row seats of the Model X. And yes, the 3rd row Model X seats likely have more room than the middle seat of the 2nd row of the I-Pace. The I-Pace is actually narrower than the E-Pace (small ICE SUV), much less the F-Pace (bigger ICE SUV). It is wider than a Bolt though... matter of fact, it's almost the same length as the F-Pace. But it is also has less height than all of those...
It will be very interesting to see if Jaguar can pull this off at a reasonable price point. It is a Model Y competitor in size, even though quite a few writers will lazily compare it against a Model X. They claim 530 liters of rear load space, but given that sharply raked rear glass, I'm not sure it has all that much more real cargo space than a Model 3 with the rear seats up.